Vacuum method for filling tires with water



May 23, 1944- w. w. MCMAHAN VACUUM METHOD FOR FILLING TIRES WITH WATER Filed July 11, 1942 atcnted May 23, 1944 VACUUM METHOD FOR FILLING WITH WATER Tinus winimrr w. MoMahan, Akron," omo, essignor to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware Application July 11, 1942, Serial No. 450,604

3 Claims.

The present invention relates to methods for filling a pneumatic tire, tube, and rim assembly substantially 100% with liquid, and, more particularly, is concerned with improved methods for lling tractor tires and the like with water.

It has been proposed heretofore to iill tractor tires with water to provide added weight and improved stability and driving characteristicsy for In the drawing the letter T indicates a pneumatic tire mounted on a rim R and containing tractor operation. Various methods have been suggested and employed for this purpose, but

substantially all of them entail filling the tire and tube assembly with liquid until a pocket of entrapped air is formed 'and then removing the trapped air from the pocket either by puncturing lthe tire and tube in the region of the pocket with subsequent sealing of the puncture or by the removal of the entrapped'air by special escape conduits.

It has long been recognized that when the tire is only partially filled with Waterand the entrapped air is left in the tire that the air will gradually seep out through the very minute pores in the tire carcass or inner tube, if one isused, and the resulting reduction of pressure in the tire is highly objectionable. On the other hand, if the tire can be filled substantially 100% with water immediately, then the tire assembly can *Y be used over very long periods of operation without any loss in tire pressure. This is apparently due to the fact that the molecules of water are sufficiently larger in size than the .molecules of air or the surface tension is greater so that water cannot pass through the very iine pores of the rubber. A

It is the vgeneral object of my invention to provide improved and less expensive methods for filling a pneumatic tire substantially 100% -with water.

Another object of my invention is the provision of a vacuum method for filling a pneumatic tire and tube assembly with liquid and including the steps of exhausting all air from the interior of the inner tube to collapse the walls thereof inwardly and then substantially simultaneously changing the sub-atmospheric pressure on the interior of the inner tube to liquid pressure to completely ll the inner tube with liquid.

For a better understanding of my invention reference should be had to the accompanying drawing wherein the single figure comprises a cross sectional representation fof a pneumaticA tire and tube assembly and a side elevation; partly in sectionsof a typicalembodiment of the apparatus for performingthe method of my invention.

ever, it should be Vparticularlyunderstood that such ribs are not necessary and are not employed inthe preferred embodiment of my invention.

One embodiment of the .apparatus for performing the method of my invention is indicated as a whole by the numeral I6 and includes a fluid jet type of suction producing mechanism having a body portion I8 formed with a longitudinal or straight through bore 20 having a central portion 22 of reduced cross section and ap,- propriately contoured to produce a Venturi tube. A conduit 23 is secured to the body portion I8 in communication with the straight through bore 20, and the conduit 22 is adapted to be connectled,`as by suitable fittingv 24, to a hose 26 or other vbe provided, if desired, with an apertured plug rand a strainer 38 which may be readily cleaned and which will .plug up in case any dirt attempts e to flow through the conduit 32 rather than hfaving the body portion I8 of the apparatus plug up.

A seat piece of rectangular metal 40 twisted through a quarter turn may be incorporated in the end of the body portion I8 in the straight through bore 20 at the-v point closest adjacent to the inlet conduit 23 in order to give the ,uuid

a whirling motion.

I provide means for by-pas'sing the iiow of fluid l through the body portion of the uid suction mechanism, and such means may comprise a conduit IM which opens through the wall of the conduit 23 and is brazed or otherwise sealed4 the conduit 5i I secure a plug valve 56 for purposes which will hereinafter be described.

In the practice of the method of my invention,

and in the operation of the apparatus, the conduit 34 of the apparatus is connected to the valve stem of theI inner tube I and the conduit 26 is connected to a source of fluid under pressure, for example water under pressure. With the valve 48 closed and the valve 56 opened water is then per mltted to iiow with considerable velocity through the conduit 23 and the straight through bore 20 of the body i8. The Venturi portion 22 of the straight through bore 20 greatly increases the speed of the water in this region of the body, and in accordance with the known operation ofiluid jet types of suction apparatus a suction is created in the region of the lateral passage 30. This suction acting through conduits 32 and 34 withdraws substantially 100% of the air out of the inner tube I. The withdrawal of air from the inner tube I causes movement of the walls of the inner tube away from the inside Walls of the tire, and

the walls of the inner tube collapse inwardly upon each other. f

This step of completely withdrawing all air from the inside of the inner tube is allowed to progress until theinner tube is completely col- In any event, the valve 56 is conveniently employed in commotion with the discharge end of the straight through bore 20 so that by closing the valve 56 it is then possible to rapidly fill the tube I with liquid and to build up in the inner tube any desired degree of internal pressure over and above atmospheric.

I with a minimum of simple instructions.

lapsed and the inside of the tube is substantially completely exhausted of air. Thereafter, the valve 48 is opened to allow the flow of water through theconduit M and into the inner tube I through the conduit 34. It will be recognized that there isa substantially instantaneous change from sub-atmospheric pressure on the inside of the inner'tube to the ow of liquid under pressure into the tube. Thus, at no time is any air allowed to get back into the inner. tube. The flow of water into the inner tube is allowed to continue under pressure into the until the inner tube has moved back into engagement with the inside walls of the tire, and the ow of water into the inner tube may be expedited by closing the valve 56, although it will be understood that the size of the aperture through the plug 38 'and the size of the lateral passage 3B is such that the much larger passages through conduits dll and 3ft will cause the lling of the inner tube when the valve d8 is opened even though the valve 56 is not closed.

thereto or thereby, but that the scope of my' invention is dened in the I claim:

l. That method of illling a pneumatic tire and inner tube mounted on a rim with liquid which includes the steps of exhausting through the valve stem all of the air out of the inner tube so as to collapse the walls of the tube inwardly against themselves and away from the inside walls of the tire, introducing liquid through the valve stem into the inner'tube to fill the tube and move the walls thereof back into engagement'with the tire, and continuing the introduction of liquid into the tube until a pressure has been built up in the tire.

2. That method of filling a pneumatic tire and inner tube mounted on a rim with liquid which includes the steps of connecting a source of subatmospheric pressure to the valve stem of the tube to collapse the tube and withdraw substantially all of the air therefrom and thereafter substantially simultaneously disconnecting the sub-atmospheric pressure and forcing liquid tube through the valve appended claims.-

stem. Y

3. That method of filling a pneumatic tire and inner tube mounted on a rim with liquid which includes the steps of connecting a source of subatmospheric pressure to the tube to collapse the tube and withdraw substantially all of the air therefrom and thereafter disconnecting the subatmospheric pressure and forcing liquid under pressure into the tube.

WILLIAM W. MCMAHAN. 

